The present invention relates to an organic electroluminescent device and, more particularly, to an organic electroluminescent device (OELD) having an optical compensation layer disposed on the transparent anode or the transparent cathode, a flat panel display and a portable electronic device using the same.
Organic electroluminescent devices can be fabricated without a backlight module as compared to liquid crystal displays thus simplifying the manufacturing process thereof. They have been rapidly developed and used in a variety of electronic devices, especially portable electronic devices such as mobile phones, game machines, video cameras, digital image reproduction apparatuses, DVD players, a personal digital assistants, or laptop computers. One of the main development issues of organic electroluminescent devices is to improve brightness, luminescence efficiency to reduce power consumption and extend product life.
U.S. Pat. No. 5,714,838 to Haight et al. discloses a top emission type organic electroluminescent device. A Calcium film or a Calcium alloy film is interposed between a transparent electrode (ZnS, GaN, ITO) and a light emitting layer in order to prevent diffusion of the compounds of the transparent electrode into the organic light emitting layer. However, the Ca film or the Ca alloy may reduce the luminescence efficiency of the organic electroluminescent device.
U.S. Pat. No. 6,831,407 to Cok discloses an organic light emitting diode. A topographical feature is located within the light emitting area to disrupt the waveguiding, whereby the light emitting efficiency of the light emitting area is improved. However, the process of the organic light emitting diode becomes relatively complex.
Therefore, there is a need to provide an organic electroluminescent device capable of improving the luminescence efficiency and simplifying the manufacturing process.